Directly: sites like Twitch are close. Indirectly: Netflix, HBO, etc. all compete for screen-based entertainment.

I also watch a lot of Youtube, outside of a couple of good movies and TV shows that I stream from my plex. So YT premium makes a lot of sense for me

Do you use Twitch? I don’t really see the direct competition besides YouTube’s small amount of live streamers that directly compete with Twitch streamers.

Tiktok is probably a better direct competitor, but I see twitch and youtube as fairly comparable

TikTok.

Also - just because it doesn't have the content that you, personally, watch, does not make it not a competitor.